In terms of organ dysfunction, kidney failure due to acute tubular necrosis and pulmonary failure are the 2 main issues. Following cardiac surgery, 11% of patients will present with transient renal dysfunction characterised by a 25% increase in serum creatinine levels and 3.5% require dialysis. The intensity of acute renal failure (ARF) is correlated to resuscitation : a 20% increase in serum creatinine levels 2 to 3 days after surgery significantly raises morbidity rates and a 50% increase raises the mortality rate to 10%.